Overview

Synonyms

Type material location

The holotype is a specimen from Palau Micronesia preserved in ethanol and deposited at the US National Museum (USNM). A whole mount and a set of serial histological sections are deposited at the Queensland Museum in Brisbane, Australia.

Diagnostic Description

The diagnostic characters of this species are the color and color pattern being dark red with small white dots and two marginal bands red and orange without dots. Presence of a prostatic vesicle with two chambers.

Description

Morphology

External anatomy: Large body with several marginal deep ruffles. The color is dark red with the dorsal surface covered by compacted small white dots given the appearance of a brilliant pink surface. There are two marginal bands, red and orange without white dots. Ventrally, the color is red being more intense towards the margin. Pseudotentacles formed by simple broad folds of the anterior margin with numerous marginal eyes. Cerebral cluster made of a large number of eyespots. Small pharynx with elaborated folds.
Internal anatomy: The male reproductive system consists of a branched vas deferens, a long seminal vesicle connected to a short ejaculatory duct, a small prostatic vesicle with two chambers, a muscular prostatic duct, and a small stylet housed in a shallow male antrum. The female system has a shallow antrum with a short vagina directed backwards surrounded by a thick and strong mass of cement gland on its first portion.

Evolution and Systematics

Taxonomic Remarks

This species was originally described by Hyman (1959) as having two male gonopores and for that reason Faubel (1984) made the new combination Pseudobiceros ferrugineus. However, in a revision of the type material, Newman & Cannon (1994) noticed the presence of a unique male gonopore and a ruffle pharynx with complex folds typical from Pseudoceros, placing this species again into the genus Pseudoceros. The species was included into the group 4 characterized by the presence of spots, dots, and mottling according to the categorization based on the color and color pattern (Newman & Cannon, 1994). P.vinosus is the only species in the same group with a red color background but it possesses yellow flecks and lacks white dots.